Old electric furnace wiring
#1
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Thread Starter
Old electric furnace wiring
I have an old Singer furnace from back in the early 70's and no wiring diagram. I was restoring it as a project and to provide heat this winter and the days are getting colder ...
I have the furnace wired up and was looking to verify that I have the 24v wiring correct.
Note: I also have a 3 amp fuse on the red wire before it goes to the thermostat.
I have the furnace wired up and was looking to verify that I have the 24v wiring correct.
Note: I also have a 3 amp fuse on the red wire before it goes to the thermostat.
#2
That is a basic electric furnace diagram and will work. You need to make sure the G terminal is active in heat mode. Usually it's not. The stat may have a switch on it for electric heat.
Typically on an electric furnace..... the G terminal is used to activate the blower by itself and the sequencer controls the blower in heat mode. This is done so that the element is shut off and the fan runs for an additional amount of time to cool the elements.
Be sure you have a high heat limit switch in the electric element line in case of blower failure.
Typically on an electric furnace..... the G terminal is used to activate the blower by itself and the sequencer controls the blower in heat mode. This is done so that the element is shut off and the fan runs for an additional amount of time to cool the elements.
Be sure you have a high heat limit switch in the electric element line in case of blower failure.
#4
It needs to. You need to check the stat for a GAS/electric heat switch or electric heat in programming.
You can post the model number of the stat for more info.
You can post the model number of the stat for more info.
#5
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Thread Starter
Electric Furnace Heater Coil Wiring
I can't remember how the coils were wired. Here is how I have them wired currently but not sure if it is right or if I should swap A and B or if it matters at all. I'm thinking it should work either way right?
Having trouble getting my heater coils to come on and trying to locate the problem.
Having trouble getting my heater coils to come on and trying to locate the problem.
#6
Keep all your work on this furnace in this thread.
A 5000 watt element would not be 120v. It would be 240v.
A 5000 watt element would not be 120v. It would be 240v.
#7
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Thread Starter
It needs to. You need to check the stat for a GAS/electric heat switch or electric heat in programming.
You can post the model number of the stat for more info.
You can post the model number of the stat for more info.
Thermostat Model is Honeywell RTH2510 / RTH2410 Series
#8
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Thread Starter
Keep all your work on this furnace in this thread.
A 5000 watt element would not be 120v. It would be 240v.
A 5000 watt element would not be 120v. It would be 240v.
The 24v system seems to work because the fan switch works and is kicking the fan on.
I'm going to wire in the transformer soon and then I'll be able to test the 24v at the base of the sequencer soon.
The heater coils were coming on a few weeks ago when I tested it but stopped working.
#9
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Thread Starter
A 5000 watt element would not be 120v. It would be 240v.
The fuse block is divided into 2 sections with 120v.
Last edited by PJmax; 12-01-18 at 11:20 PM. Reason: new diagram
#10
You need to stop thinking of two 120v lines. You are working with 240v.
Two 120v legs don't always yield 240v.
You need a line from Leg A and a line from Leg B. Yes..... individual they are 120v but if you had two 120v lines from Leg A..... that would not yield 240v.
I redrew your diagram.
Two 120v legs don't always yield 240v.
You need a line from Leg A and a line from Leg B. Yes..... individual they are 120v but if you had two 120v lines from Leg A..... that would not yield 240v.
I redrew your diagram.
#11
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Thread Starter
Two 120v legs don't always yield 240v.
So trying to think how I can run 240v lines to the sequencer.
Maybe I'm misunderstanding and your saying that A and B totals 240v to the heater coil?
Last edited by Toolman Dan; 12-02-18 at 12:12 AM.
#13
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Thread Starter
Measure across the two blocks. You should see 240v.
Last edited by Toolman Dan; 12-02-18 at 12:37 AM.
#14
Only one line gets switched. Look at the drawing I did. One line goes to the element. The second line goes thru the sequencer. The red is one 120v path and the black is the other 120v path.
#15
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Only one line gets switched. Look at the drawing I did. One line goes to the element. The second line goes thru the sequencer. The red is one 120v path and the black is the other 120v path.
I'll make these changes and get back with you. Hopefully the elements will come on this time.
#16
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Thread Starter
Fan Wiring
Typically on an electric furnace..... the G terminal is used to activate the blower by itself and the sequencer controls the blower in heat mode. This is done so that the element is shut off and the fan runs for an additional amount of time to cool the elements.
Additional Note:
I'm using the BLACK wire from the fan which currently is giving me the fast speed. I did this because I replaced the old coils with new ones and I fear that they will burn up. I was reading that when the heat runs it is supposed to be the RED wire which is the one step down from the fast speed. Is it OK to use this speed until I feel more comfortable and then step it back down?
#17
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Thread Starter
Update
The elements came on but the fan shut off way too soon.
The elements were still glowing after the fan shut off.
The elements were still glowing after the fan shut off.
#18
In order to accomplish what you want...... you need to replace your single pole relay with a single pole double throw. As shown in the diagram..... when there is no power on the G terminal..... the relay is normally closed. That will allow the sequencer to control the blower. When you power the G terminal..... the fan will run. Change the stat programming or switch back to gas furnace and the G will not be energized in heat mode.
With a 5kw element..... medium speed should be ok. You'd have to monitor the high heat safety stat. You don't want it opening when the furnace is running normally.
With a 5kw element..... medium speed should be ok. You'd have to monitor the high heat safety stat. You don't want it opening when the furnace is running normally.
#19
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Thread Starter
Single Pole Double Throw
you need to replace your single pole relay with a single pole double throw
Change the stat programming or switch back to gas furnace and the G will not be energized in heat mode
I wired the fan switch just like the drawing and I blew a fuse.
The fuse that blew is where the wire runs from the fuse block to the sequencer.
#20
I can't help you on the specific sequencer wiring without it's full part number. Every one is different.
#21
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Thread Starter
I can't help you on the specific sequencer wiring without it's full part number. Every one is different.
I'm going to try and restore the wiring diagram. The blower caught on fire 10 years ago and the diagram has mold and fire damage from that fire. I'm thinking that the wire arrangement at the fuse box is EXTREMELY important and has something to do with the fuse blowing. Balancing this load at the fuse block is probably REALLY vital. I'll get back with you.
#22
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Thread Starter
Fuse Block Load Balancing and Wiring
Singer BCE23000
Date 9-12-73
The wiring is close to matching furnace diagram.
Looks like there was some load balancing too.
The original diagram shows a 6 pole fan switch.
Date 9-12-73
The wiring is close to matching furnace diagram.
Looks like there was some load balancing too.
The original diagram shows a 6 pole fan switch.